whats the brightest HID look you can get with stock headlights on a 1991 ls400? right now i have silverstar, but i heard they burn out easy. and their not as "HID" as i thought they would be. does anyone have any suggestions? or what do i have to do to change my stock headlights, to hid headlights?

 

You have seen about the best there is. Some PIAA's give better light IMO but not enough that you will notice unless you do a side by side.

HID's are the way to go to get brighter but in a non-HID housing the beam will be too scattered to really take advantage of it. A projector retrofit or swap to a HID headlight specific for your car is the proper way. I don't know enough about your model to suggest one over the other. You might want to search the forum for you year LS for more info.